Ketamine for MS Fatigue

Inclusion Criteria: Female and Male patients with any form of CDMS ages 18-65 inclusive Report fatigue which is interfering with QOL Able and willing to sign informed consent Stable on DMT for at least 3 months prior to baseline visit Not experiencing an MS relapse within 90 days prior to baseline visit. Must agree to practice an acceptable method of contraception Experiencing significant fatigue due to MS (MFIS of ≥10) Exclusion Criteria: Allergy to Ketamine Taking medications which may interact with ketamine Change in DMT within 3 months prior to baseline visit MS relapse within 90 days of the baseline visit Confirmed diagnosis of untreated Sleep Apnea Confirmed diagnosis of periodic limb movement disorder Serious infection in the 30 days prior to baseline visit. Patients with significant comorbid conditions: Untreated hypertension (SBP>160, DBP>100 at baseline) Liver disease Significant renal disease History of cardiac arrhythmia Any comorbidities which at the opinion of the investigators post undue risk Current alcohol or drug abuse Participation in another interventional clinical trial in the past 3 months. Pregnant or lactating Any condition which in the opinion of the investigators will cause safety concerns for the patient, or inability to comply with the protocol.